The provision of dyes is key in many fields of technology, for instance in the preparation of cosmetic, personal care and health compositions, detergent compositions and in printing technologies, to name but a few.
Particles incorporating dyes for use in these fields are described in WO-A-2004/081222. This document describes a process for manufacturing encapsulated dyes using the well-known sol-gel methodology, which is an emulsion technique resulting in a core/shell structure (a core of dye surrounded by a shell of a material, such as silica). Further examples of particles of the art are found in US-A-2005/0276774 and US-A-2005/0265938, which describe the production of such particles by dispersive techniques and micelle formation respectively. However, particles made according to the processes described in these documents often exhibit dye leakage, which is clearly undesirable.
Accordingly, there is a need for a new and effective process for the encapsulation of dyes, which results in particles from which there is negligible to no leakage of the dyes over their lifetime.